Combustion device



E. W. PELSTER GOMBUSTION DEVICE Dec. 16, 1930.

Filed Dec. 3. 1927 Patented Dec. 16, 1930 PATENT @FFECE EDWIN W. PELSTER, F ST. LOUIS, MISSOURI COMBUSTION DEVICE Application led December 3, 1927. Serial No. 237,477.

My invention relates to combustion devices and more particularly to combustion devices used with steam boilers and adapted to burn soft or bituminous coal which ordinarily when burned creates dense smoke which passes up the chimney and into the atmosphere.

Heretofore many forms of devices have been attached to furnaces and have been incorporated therein in an attempt to prevent the creation of dense smoke which passes from the chimney. However, such devices which would prevent even to a small degree the creation of smoke which passed from the chimney, required either considerable skill in ring the furnace or complicated or eX- pensive mechanism so that their common use was precluded.

The objects of my invention are to provide a combustion device which will bring about the more complete combustion of the volatile gases which ordinarily pass unburned into the youter air and to provide a combustion device which will effectually prevent the gases of combustion from passing from the chimney to the atmosphere in the form of dense smoke.

One embodimentof my invention is somewhat diagrammatically shown in its simplest form in the accompanying drawings.

However, I do not purpose to limit my invention to the use of this form of furnace since my device may be successfully installed in furnaces in boilers of any type. In the accompanying drawings wherein similar letters are used to designate similar parts: Fig.

l is an elevation, partly in section, of my device installed in combination with a furnace of a small upright boiler, and Fig. 2 is a detail of construction.

Referring to the figures, the furnace shown therein as embodying my invent-ion has a combustion chamber A with a suitable grate B and an ash pit C. The boiler D has the iue pipes E extending upwardly therethrough and terminating at their upper ends just below the opening into the stack flue F through which the gases of combustion pass from the furnace. The stack flue F may have an opening G in the side Wall thereof, as shown in Fig. 1, in which opening is fixed an air inlet pipe H. At the outer end of the air inlet pipe H is a damper J arranged to be opened or closed by movement of the rod L whereby the flow of air through the air inlet pipe H and, in turn, into the stack flue F through the opening Gr may be regulated.

A nozzle M is positioned in the stack iiue F, as shown, at a. point more remote from the furnace than the opening Gr. The nozzle M may be of any suitable form, but I prefer that the nozzle be arranged so that the jets of steam therefrom, as will be more fully hereinafter explained, will be ejected radially and in a direction substantially transversely of the stack flue F. The flue shown in the drawings is formed of an ordinary pipe threaded at its outer end and slotted as at N and then fitted with a suitable cap O, as shown in detail in Fig. 2. In this form of my invention the nozzle M is connected by suitable pipes to two sources of steam supply. ()ne pipe P leads from the boiler of the furnace and another pipe Q leads from the mainl exhaust pipe Q of an engine R adapted to be operated by steam from the boiler of the furnace in which my device is embodied. The main exhaust pipe Q, and the auxiliary exhaust pipe Q are provided with valves T and T, respectively, by which the flow of steam therethrough may be regulated.

The operation of this embodiment of my. invention is as follows After the fire is started the damper J is moved to allow the proper amount of air to How through the air inlet pipe H and through the opening G into the stack flue F and there combine with the gases of combustion passing into the stack flue F from the combustion chamber A of the furnace. I prefer that the air inlet pipe H be formed and arranged as shown in the drawings so that the air will be at atmospheric pressure when it is admitted to the stack flue F to combine therein with the gases of combustion. The valve S in the steam pipe P is opened and the valve T in the exhaust steam pipe Q is closed. As steam is generated in the boiler it will pass through the pipe P and be ejected through the nozzle M into the stack flue F, as de- Cil scribed. Since the steam is ejected into the stack flue after the gases of combustion have been more or less diluted with air through the inlet I-I, the flow of dense smoke from the stack flue into the at-niosphere will be virtually eliminated. Also, I have found from practice that the injection of steam into the Hue F creates, in effect, a forced draft, because as the steam passes outwardly through the flue it creates a slight suction in the lower part of the flue. Then the steam engine R is started in operation the valves T and T in the steam pipe Q and Q. are adjusted to get the proper flow therethrough, and they valve S in the steam pipe I) may be closed and the proper amount of exhaust steam from the engine R ejected into the stack flue F through the nozzle M, thereby effecting a saving of fuel. The admission of cool air through the air inlet pipe I-I tends to cool the gases of combustion in the flue F and thereby reduce the draft therein, but this reduction of draft 'is more than made up by the draft created by the injection of steam into the flue F through the nozzle M. rllhe cool air entering through the pipe H comes in Contact with the steam from the nozzle M and thereby forms a vapor which seizes and holds the line particles of soot and thus prevent them from floating around in the atmosphere after they have left rthe chimney. Some of these vapor coated particles may drop back to the base of the stack flue, but most will be carried upwardly and discharged from the stack and fall in a. very short time to the earth. The injection of steam in addition to washing the solid particles of soot from the products of combustion also gives the products of combustion a whitish color as they emerge from the upper end of the stack. The result of this is that there is practically no black smoke emitted from the chimney, but if anything the smoke is of a. whitish gray color.

Vhile I prefer to discharge the steam from the nozzle l\[ into the stack F in a direction substantially at right angles to the axis thereof I may incline the discharge so as to make the angle with the axis less than a right angle. Then the angle of discharge makes an angle less than a right angle with the axis of the stack a somewhat greater draft is created than when the angle of discharge with the axis of a stack is a right angle.

I do not propose to limit my invention to the exact details of construction shown in the drawings since it will be readily understood that the size, shape and arrangement of the various parts may be changed and modified within wide limits without deviating from the spirit of my invention as defined in the claim included below.

That I claim as new and desire to secure by Letters Patent, is:

In combination with a furnace, a flue for the passage of the gases of combustion from said furnace, said Hue having an opening in a wall thereof arranged to allow air to flow through said opening into said flue and combine with said gases of combustion, means for controlling the fiow of air through sai-d opening, a nozzle positioned in said flue at a point more remote from said furnace than said opening for air, and a connection between said nozzle and a source of steam supply, said nozzle being arranged axially in the flue and formed to deliver steam ets radially and substantially transversely of said flue.

In witness whereof I have signed my name to the foregoing specification.

EDWIN W. PELSTER. 

